From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E8EEC83003 for ; Thu, 30 Apr 2020 02:23:00 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E728C20787 for ; Thu, 30 Apr 2020 02:22:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="FtvjsTEW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E728C20787 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:44286 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jTyqp-0005K7-4H for qemu-devel@archiver.kernel.org; Wed, 29 Apr 2020 22:22:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38986) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jTyna-0003sL-77 for qemu-devel@nongnu.org; Wed, 29 Apr 2020 22:22:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.90_1) (envelope-from ) id 1jTymv-0002aa-J3 for qemu-devel@nongnu.org; Wed, 29 Apr 2020 22:19:37 -0400 Received: from mail-pf1-x42e.google.com ([2607:f8b0:4864:20::42e]:46236) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jTymv-0002OT-3p for qemu-devel@nongnu.org; Wed, 29 Apr 2020 22:18:57 -0400 Received: by mail-pf1-x42e.google.com with SMTP id 145so2112603pfw.13 for ; Wed, 29 Apr 2020 19:18:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=twoExpS4ocZ6juaajIgOBNECgpi7S7qKtK1d8Rwr6MA=; b=FtvjsTEW5mJSme3O/c/bmV+UgHDTf0333rjk2eSTfNj+VKAtNwCVyam55I+P5mYHVl k0/yOBGDpQVxCc0RL44JvGeQ3zdgqBhv4TXaDDMRVSBWdfKkrRbTqIKzY+u/y4c72Cbi O9uIm4S8XK4B3d33o++7plCCZlWHbNuR9F90cZnVy5ZKhfLpuvY9Ug5IyifrW7GFjmE6 +MMwuMfDylLZ1QdkI8LuKJ1ba0sTSolcB7wOAa7wfhQo6RewGzIebfgjVKrSYYDbSxZE Ix/QWRpIWHxlhmNPiZt9MuMo5dJleprIE9hMQ5OarzTVohx32H6V4XUWeVS72x6G+iQ5 VjUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=twoExpS4ocZ6juaajIgOBNECgpi7S7qKtK1d8Rwr6MA=; b=B71nxtf1scpLjoHSGVdBCK1dpiLcVcPjBbVdlwj8lauBZPLwsqZUQ9S2VhFkLjCBYc sBAXlXjHLPpXAkeAWrjeOz+BoEDKsuOjR53NacKLylZgwfG9/BkeddbW8zxDPHp2nRa7 Zfuwgw/KxSD0E8VdxLxRKAnxJUqWryYv9zTGe7H2Snj2NSdf2QVvTZ0UTjFKlLRaCp3g uqa4j8vnLyGH4OtYMCx542oozr4VYCWAJCgSVxmxOcuF23r6f8xHXxV+dYqIXpcoz+5q G8065Ks9FXN8w58RRiiBc9CJnk1dBUEDMPmBEIcGdUjDJj8S6TXaenXyuWqL+q9flmXa URRA== X-Gm-Message-State: AGi0PubPe9SrjpH78CGvnctYZYe3pw8vMDC3SKwwhJTX8kBhC5tsvjyl ad1sk8DV45hyS7RZKcEqQKSZRg== X-Google-Smtp-Source: APiQypK0sdI29skL0sgmo2t7rlhk9TvvZIoKmKNjnd254EpJW1TvRqb9PaYoXAv2bNKbJPZn66/9wg== X-Received: by 2002:a62:fccf:: with SMTP id e198mr1155862pfh.119.1588213135411; Wed, 29 Apr 2020 19:18:55 -0700 (PDT) Received: from [192.168.1.11] (174-21-149-226.tukw.qwest.net. [174.21.149.226]) by smtp.gmail.com with ESMTPSA id w9sm2156864pff.101.2020.04.29.19.18.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 29 Apr 2020 19:18:54 -0700 (PDT) Subject: Re: R: R: About hardfloat in ppc To: luoyonggang@gmail.com, =?UTF-8?Q?Alex_Benn=c3=a9e?= References: <87lfmhl0xa.fsf@linaro.org> <87imhlkwun.fsf@linaro.org> <87ftcoknvu.fsf@linaro.org> <871ro6ld2f.fsf@linaro.org> <87sggmjgit.fsf@linaro.org> From: Richard Henderson Message-ID: <43ac337c-752a-7151-1e88-de01949571de@linaro.org> Date: Wed, 29 Apr 2020 19:18:52 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::42e; envelope-from=richard.henderson@linaro.org; helo=mail-pf1-x42e.google.com X-detected-operating-system: by eggs.gnu.org: Error: [-] PROGRAM ABORT : Malformed IPv6 address (bad octet value). Location : parse_addr6(), p0f-client.c:67 X-Received-From: 2607:f8b0:4864:20::42e X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Cave-Ayland , "qemu-devel@nongnu.org" , Programmingkid , "qemu-ppc@nongnu.org" , Howard Spoelstra , Dino Papararo Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 4/29/20 5:20 PM, 罗勇刚(Yonggang Luo) wrote: > Question, in hard-float, if we don't want to read the fp register. > for example: If we wanna compute c = a + b in fp32 > if c = a + b In hard float > and if b1 = c - a in hard float > if b1 != b at bitwise level, the we se the inexat to 1, otherwsie  > we set inexat bit to 0? are this valid? > > we can also do it for a * b, a - b, a / b.  > That does seem plausible, for all of the normal values for which we would apply the hard-float optimization anyway. But we already check for the exceptional cases: if (unlikely(f32_is_inf(ur))) { s->float_exception_flags |= float_flag_overflow; } else if (unlikely(fabsf(ur.h) <= FLT_MIN)) { if (post == NULL || post(ua, ub)) { goto soft; } } r~